The following relates generally to wireless communication, and more specifically to a physical uplink control channel (PUCCH) design for enhanced machine type communications (eMTC) in a shared or unlicensed spectrum.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as a Long Term Evolution (LTE) systems or LTE-Advanced (LTE-A) systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
Certain wireless communications systems may include machine type communication (MTC) devices (e.g., UEs) communicating in designated radio frequency bands. For example, an MTC device may include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application. Certain radio frequency bands, however, may be configured such that any devices communicating in the radio frequency bands must meet various communication configuration protocols (e.g., maximum transmit power, power spectral density (PSD) requirements, bandwidth constraints, and the like). While many uplink and/or downlink channel communications may satisfy these protocols, other types of communications (e.g., PUCCH communications for MTC (or eMTC) devices) may need to be designed to comply with the protocols for a particular radio frequency band.